This invention relates to the production of poly(arylene sulfide sulfone)s. In one aspect, this invention relates to the production of poly(phenylene sulfide sulfone). In another aspect, this invention relates to the production of poly(arylene sulfide sulfone)s exhibiting high molecular weight. In a further aspect, this invention relates to the production of poly(phenylene sulfide sulfone) exhibiting high molecular weight.
Poly(arylene sulfide sulfone)s are engineering thermoplastics of potential commercial interest for film, fiber, molding, and composite applications because of their high glass transition temperatures and chemical resistance.
General processes for the production of poly(arylene sulfide sulfone)s are known. Poly(arylene sulfide sulfone)s can be prepared by the reaction of a polyhalo aromatic sulfone, such as bis(4-chlorophenyl)sulfone, with an alkali metal sulfide in the presence of a polar organic compound.
U.S. Pat. No. 4,016,145 discloses the use of alkali metal carboxylate and U.S. Pat. No. 4,127,713 discloses the use of sodium carboxylate to increase the molecular weight of poly(arylene sulfide sulfone)s. Although these patents represent significant and valuable advances in the art, there is a need for a process which can provide high molecular weight poly(arylene sulfide sulfone)s without the problems associated with using higher levels of alkali metal carboxylate. Use of increased levels of alkali metal carboxylate results in increased production costs for poly(arylene sulfide sulfone) which is commercially undesirable. Furthermore, increased levels of alkali metal carboxylate can result in waste water disposal problems due to entrainment of organic acids. It has now been discovered that unexpectedly good results can be obtained using very low levels of alkali metal carboxylate in the production of poly(arylene sulfide sulfone)s.